This invention relates to molded hopper tees, and more particularly, to an integral one-piece molded hopper tee having generally transversely extending hollow pipe sections, each integrally molded from a rigid and durable polymer material, and having metal reinforcing elements molded in-situ within and adjacent outer free ends of the transversely extending hollow pipe sections.
It is well known that large hopper trucks or tank trailers are commonly used to transport bulk commodities, such as industrial and food products, from the supplier to the ultimate manufacturer, who converts the bulk commodity into products for consumers. The bulk commodity is pneumatically unloaded from the hopper truck or tank trailer into clean and sanitary pipe lines at the manufacturer's location. In order to provided the desired pneumatic unloading of the bulk commodity, a hopper tee is mounted to the discharge outlet of the hopper truck or tank trailer in order to transfer the bulk commodity, by gravity flow, air pressure and/or vibration into a generally vertically extending hollow pipe section of the hopper tee. The hopper tee also includes a transverse or horizontally extending hollow pipe section, connected to the generally vertically extending hollow pipe section, and allowing the outer ends of the generally horizontally extending hollow pipe section to be connected in the pneumatic pipeline tubing system of the manufacturer, for pneumatic unloading purposes As will be appreciated, pneumatic unloading of the bulk commodity, through at least the horizontal hollow pipe section and the pipe line tubing, is achieved by establishing a pressure differential in the manufacturer's pipeline system.
In the construction of prior art hopper tees, the generally vertically and horizontally extending hollow pipe sections have been welded together, as shown, for example, in the prior art drawing illustrations of my prior co-pending patent application Ser. No. 186,104, identified above. As was explained in this prior co-pending application, the welds in the area of juncture between the vertical and horizontal hollow pipe sections of the hopper tee produced rough and irregular internal wall surfaces, which not only substantially impeded product flow, but resulted in a much higher incident of product hang-up do to the rough and irregular internal wall surface areas. This resulted in product contamination. In addition, some abrasive dry bulk commodities, such as sand, cause premature wear-through of the hopper tee, particularly in the welded areas of juncture between the generally vertically and horizontally extending hollow pipe sections, and even through the entire hopper tee. As a result, most hopper tees, as well as the piping used for unloading, are typically made from schedule 80 type steel, in order to hold up to the abrasiveness of sand, or other similar materials.
In my aforementioned prior co-pending patent application Ser. No. 186,104, there is disclosed a cast hopper tee in which the area of juncture between the generally vertically and horizontally extending hollow pipe sections is provided with smooth and uninterrupted internal transitional services, permitting complete and continuous flow of product discharge from the hopper and into the generally vertically extending hollow pipe section in order to flow without impedance into the second generally horizontally extending hollow pipe section and then through the pipeline tubing. In addition to the aforementioned construction of the cast hopper tee, an inner molded lining from a polymer material having a low coefficient of friction may be used along the internal cylindrical walls including the smooth and uninterrupted internal transitional surfaces of the generally vertically and horizontally extending hollow pipe sections. In general, it was discovered that a urethane elastomeric lining not only provides a low coefficient of friction, but also has good abrasion resistance and good load bearing characteristics. When used with a cast aluminum hopper tee, the resulting product creates a lighter cast hopper tee having an inner molded polymer lining providing abrasion resistance equal to or better than the schedule 80 heavy steel, and yet resulted in a much lighter cast hopper tee, with greater pay load, which is extremely beneficial to users.
The present invention is a further extension and development of the various constructions employed in my prior co-pending application in that an entire one-piece molded polymer tee may be formed from a rigid and durable polymer material, together with additional reinforcing elements, to provide a hopper tee which is not only strong and durable in use in the intended environment, but which has a much lighter weight than all previously known prior art constructions, as well as those disclosed in my aforementioned co-pending patent applications.